[PATCH 1/6] KVM: arm64: Use visibility hook to treat ID regs as RAZ

Oliver Upton
2022-08-17T21:49:35Z

The generic id reg accessors already handle RAZ registers by way of the
visibility hook. Add a visibility hook that returns REG_RAZ
unconditionally and throw out the RAZ specific accessors.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
arch/arm64/kvm/sys_regs.c | 33 ++++++++++++++-------------------
1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 3234f50b8c4b..e18efb9211f0 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1145,6 +1145,12 @@ static unsigned int id_visibility(const struct kvm_vcpu *vcpu,
return 0;
}

+static unsigned int raz_visibility(const struct kvm_vcpu *vcpu,
+ const struct sys_reg_desc *r)
+{
+ return REG_RAZ;
+}
+
/* cpufeature ID register access trap handlers */

static bool __access_id_reg(struct kvm_vcpu *vcpu,
@@ -1168,13 +1174,6 @@ static bool access_id_reg(struct kvm_vcpu *vcpu,
return __access_id_reg(vcpu, p, r, raz);
}

-static bool access_raz_id_reg(struct kvm_vcpu *vcpu,
- struct sys_reg_params *p,
- const struct sys_reg_desc *r)
-{
- return __access_id_reg(vcpu, p, r, true);
-}
-
/* Visibility overrides for SVE-specific control registers */
static unsigned int sve_visibility(const struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
@@ -1262,12 +1261,6 @@ static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
return __set_id_reg(vcpu, rd, val, raz);
}

-static int set_raz_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
- u64 val)
-{
- return __set_id_reg(vcpu, rd, val, true);
-}
-
static int get_raz_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
u64 *val)
{
@@ -1374,9 +1367,10 @@ static unsigned int mte_visibility(const struct kvm_vcpu *vcpu,
*/
#define ID_UNALLOCATED(crm, op2) { \
Op0(3), Op1(0), CRn(0), CRm(crm), Op2(op2), \
- .access = access_raz_id_reg, \
- .get_user = get_raz_reg, \
- .set_user = set_raz_id_reg, \
+ .access = access_id_reg, \
+ .get_user = get_id_reg, \
+ .set_user = set_id_reg, \
+ .visibility = raz_visibility \
}

/*
@@ -1386,9 +1380,10 @@ static unsigned int mte_visibility(const struct kvm_vcpu *vcpu,
*/
#define ID_HIDDEN(name) { \
SYS_DESC(SYS_##name), \
- .access = access_raz_id_reg, \
- .get_user = get_raz_reg, \
- .set_user = set_raz_id_reg, \
+ .access = access_id_reg, \
+ .get_user = get_id_reg, \
+ .set_user = set_id_reg, \
+ .visibility = raz_visibility, \
}

/*
--
2.37.1.595.g718a3a8f04-goog